The international Transplantation Society is composed of physicians, surgeons and immunologists interested in the science and practical application of organ and tissue transplantation. The XIIIth international Congress of the Transplantation Society will be held in San Francisco, CA, August 19-24, 1990. The main objectives of the Congress are to discuss and explore current issues in organ transplantation, both clinical and experimental and to give particular attention to the areas in which the most rapid and fruitful progress is being made. Certain fields that are related to organ transplantation, such as tumor immunology may be included. The biennial Congresses of the transplantation Society provide the only international forum at which all divisions of the field are represented. Participants are given the opportunity to gain current views of new areas of research and clinical application. Papers are selected from abstracts submitted by both members of the Society and nonmembers. Both society members and nonmembers are provided the optimal conditions for dissemination of their data and concepts and for fruitful and intellectual interactions that may lead to new advances. Participants will be from the USA, Canada, West Europe, Japan, China, Korea, Australia, Eastern Europe, Africa, Israel, Mexico and South America. The diversity of interests among the participants will be reflected by the program. The Congresses have always attracted a large number of young scientists, many of whom are at the beginning of their scientific careers. The Congress gives them the opportunity to meet and interact with firmly established investigators. The travel grants that the NIH have provided in the past have been indispensible in helping young American investigators attend the Congress. The support requested in this grant is for travel grants for young American investigators. The recipients of the travel grants will be selected by a committee of senior US investigators and representatives of the NIH.